Question

In the Winter of 1994, fifteen percent of all pediatric outpatient visits at a particular clinic were due to a single strain of flu. An investigator hypothesizes that the proportion of visits due to flu will decrease if patients are provided with flu shots. Suppose that flu shots are given to a random sample of 125 pediatric patients in the fall of 1995. These patients are tracked over the following winter to assess whether or not they come to clinic for flu (visits for other illnesses or injuries are not counted). Twelve percent of these patients are seen in the pediatric clinic in the Winter of 1995 for flu. Based on the data, is there evidence of a significant reduction in the proportion of the patients seen in the clinic for flu after receiving the flu shot? Use 5% level of significance

Answer 1